1. Technical Field
The present invention relates to a liquid jet head and a liquid jet apparatus.
2. Related Art
Conventionally, there has been used an ink jet printer (liquid jet apparatus) that is provided with an ink jet head (liquid jet head) as an apparatus that ejects ink in the form of liquid droplets onto a recording paper (recording medium) to record an image or a character thereon.
Generally, an ink jet head is provided with a nozzle plate which has a nozzle array including a plurality of nozzle holes, an actuator plate which has a plurality of channels communicating with the respective nozzle holes, and a cover plate which has a common ink chamber communicating with the channels. In such a configuration, a channel is caused to contract to increase the pressure inside thereof, thereby ejecting ink inside the channel from the corresponding nozzle hole to allow the ink to adhere on a recording paper.
However, in the above ink jet head, for example, pressure fluctuation inside a channel which occurs when ejecting ink is disadvantageously transmitted as a pressure wave to the common ink chamber and the other channels through the common ink chamber, which affects the ejection performance (printing stability). Specifically, a pressure wave which is generated when driving one or more channels is transmitted to the common ink chamber, and affects ejection of ink as a frequency component other than a resonance frequency of a pressure wave to be generated for ejecting ink inside the other channels. As a result, influence such as an increase or decrease in the speed of the ejection is caused. At the same time, the volume of ink droplets also decreases or increases, which affects the image quality on a recording paper. In addition, the pressure fluctuation becomes large when the ejection amount per unit time increases or the size of liquid droplets increases.
For example, JP 2005-14618 A discloses a so-called edge shoot type head chip in which nozzle holes are arranged on first ends in the extending direction of channels, and ink is supplied into the channels from a common ink chamber which is arranged on second ends in the extending direction of the channels. In the disclosed head chip, a thin pressure fluctuation buffering portion is formed in the common ink chamber in order to buffer pressure fluctuation inside the common ink chamber.